脉冲电流对Ti-6Al-4V冷拉拔变形行为的影响(英文)

利用电子背散射衍射(EBSD)及透射电镜(TEM)研究在脉冲电流作用下Ti-6Al-4V钛合金冷拉拔变形后组织及织构的演变。研究结果表明:施加脉冲电流可以促进非有利滑移取向的晶粒发生变形,从而使Ti-6Al-4V钛合金各晶粒之间的变形更为协调。常规拉拔和电塑性拉拔的丝材织构对比显示,脉冲电流促进钛合金柱面,a滑移,抑制锥面c+a滑移,通过晶界滑移协调c方向应变。电塑性拉拔钛合金的小角度晶界比例降低,说明脉冲电流抑制了变形诱发伴生位错晶界和几何必须晶界的形成。

Effect of electropulsing on deformation behavior of Ti-6Al-4V alloy during cold drawing

Electron backscattered diffraction （EBSD） and transmission electron microscopy （TEM） were used to investigate effect of electropulsing on microstructure and texture evolution of Ti-6Al-4V during cold drawing. Research results demonstrate that the electropulsing treatment （EPT） can enhance the deformability of the grains with unfavorable orientations, which makes the compatibility of deformation among grains much better. A comparison in texture evolution between conventional cold drawing and EPT cold drawing indicates that the EPT promotes prismatic 〈a〉 slip moving, restricts pyramidal 〈c＋a〉 slip occurring and accommodates the deformation with c-component by grain boundary sliding. The fraction decrease of low-angle grain boundaries for samples deformed with EPT reveals that the application of electropulsing restricts the formation of the incidental dislocation boundaries and the geometrically necessary boundaries.